android倒计时功能实现

最近项目要求做一个倒计时功能，进入答题界面前开始弹框倒计时3,2,1，倒计时完成弹框消失之后请求数据，答题计时开始10,9,8…3,2,1。
倒计时一直都用CountDownTimer,但是在界面展示进度和播放声音的时候总是有一些误差，开始计时的时候太快了以及执行onFinish()方法延迟，于是自己仿写了一个CountDownUtil用于倒计时操作。


CountDownUtil代码如下

package com.spring.countdowndemo;

import android.os.Handler;
import android.os.Message;

/**
 * Created by Administrator on 2018/7/9.
 * 自定义倒计时
 */

public class CountDownUtil {

    private static final int MSG = 1;
    /**
     * 倒计时时长已毫秒为单位
     */
    private final long mMillisInFuture;

    /**
     * 每隔多少毫秒记一次时
     */
    private final long mCountdownInterval;
    /**
     * boolean representing if the timer was cancelled
     */
    private boolean mCancelled = false;

    private long mDuration;//时长 毫秒为单位

    public CountDownUtil(long millisInFuture, long countDownInterval, CountDownListener countDownListener) {
        mMillisInFuture = millisInFuture;
        mCountdownInterval = countDownInterval;
        mCountDownListener = countDownListener;
    }

    /**
     * Cancel the countdown.
     */
    public synchronized final void cancel() {
        mCancelled = true;
        mHandler.removeMessages(MSG);
    }

    /**
     * 开始计时
     */
    public synchronized final CountDownUtil start() {
        mCancelled = false;
        mDuration = mMillisInFuture;

        if (mMillisInFuture <= 0) {
            if (mCountDownListener != null) {
                mCountDownListener.onFinish();
            }
            return this;
        }
        if (mCountDownListener != null) {
            mCountDownListener.onTick(mDuration);
        }
        mHandler.sendMessageDelayed(mHandler.obtainMessage(MSG), mCountdownInterval);
        return this;
    }

    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            if (mCancelled) {
                return;
            }
            mDuration -= mCountdownInterval;
            if (mDuration <= 0) {
                if (mCountDownListener != null) {
                    mCountDownListener.onFinish();
                }
            } else {
                if (mCountDownListener != null) {
                    mCountDownListener.onTick(mDuration);
                }
                mHandler.sendMessageDelayed(obtainMessage(MSG), mCountdownInterval);
            }

        }
    };
    private CountDownListener mCountDownListener;

    public void setCountDownListener(CountDownListener countDownListener) {
        this.mCountDownListener = countDownListener;
    }

    public interface CountDownListener {
        /**
         * 倒计时
         */
        void onTick(long millisUntilFinished);

        /**
         * 倒计时完成
         */
        void onFinish();

    }
}

倒计时弹框代码如下

package com.spring.countdowndemo;

import android.app.Dialog;
import android.content.Context;
import android.support.annotation.NonNull;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.ScaleAnimation;
import android.widget.TextView;

/**
 * Created by Administrator on 2018/6/15.
 * 倒计时弹框
 */

public class CountDownDialog extends Dialog implements CountDownUtil.CountDownListener {

    private static final long DURATION = 3000;
    private static final long INTERVAL = 1000;

    private TextView tvCountdown;

    private CountDownUtil timerCountDown;
    private VolumeUtil volumeUtil;
    private AlphaAnimation alphaAnimation;
    private ScaleAnimation scaleAnimation;

    public CountDownDialog(@NonNull Context context) {
        this(context, R.style.customDialog);
    }

    public CountDownDialog(@NonNull Context context, int themeResId) {
        super(context, themeResId);

        Window window = getWindow();
        window.setGravity(Gravity.CENTER); // 此处可以设置dialog显示的位置
        WindowManager.LayoutParams params = window.getAttributes();
        params.width = WindowManager.LayoutParams.WRAP_CONTENT;
        params.height = WindowManager.LayoutParams.WRAP_CONTENT;
        getWindow().setAttributes(params);
        setCancelable(false);
        setCanceledOnTouchOutside(false);

        LayoutInflater factory = LayoutInflater.from(context);
        View view = factory.inflate(R.layout.dialog_answer_countdown, null);
        setContentView(view);
        tvCountdown = findViewById(R.id.tv_countdown);

        volumeUtil = new VolumeUtil();
        alphaAnimation = new AlphaAnimation(0, 1);
        scaleAnimation = new ScaleAnimation(0.5f, 1.5f, 0.5f, 1.5f,
                Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);

        timerCountDown = new CountDownUtil(DURATION, INTERVAL, this);
        timerCountDown.start();

    }


    @Override
    public void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        volumeUtil.releaseMusic();
        if (alphaAnimation != null) {
            alphaAnimation.cancel();
            alphaAnimation = null;
        }
        if (scaleAnimation != null) {
            scaleAnimation.cancel();
            scaleAnimation = null;
        }
    }

    @Override
    public void onTick(long millisUntilFinished) {
        volumeUtil.playMusic(getContext(), R.raw.audio1);
        tvCountdown.setText(millisUntilFinished / INTERVAL + "");
        // 设置透明度渐变动画

        //设置动画持续时间
        alphaAnimation.setDuration(INTERVAL / 2);
        tvCountdown.startAnimation(alphaAnimation);
        // 设置缩放渐变动画
        scaleAnimation.setDuration(INTERVAL / 2);
        tvCountdown.startAnimation(scaleAnimation);
    }

    @Override
    public void onFinish() {
        volumeUtil.playMusic(getContext(), R.raw.audio2);
        dismiss();
    }
}

弹框样式

倒计时控件代码如下

package com.spring.countdowndemo;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;

/**
 * Created by Administrator on 2018/6/11.
 * 倒计时控件
 */

public class CountTimeView extends View {

    // 画实心圆的画笔
    private Paint mCirclePaint;
    // 画圆环的画笔
    private Paint mRingPaint;
    // 画圆环的画笔背景色
    private Paint mRingPaintBg;
    // 画字体的画笔
    private Paint mTextPaint;
    // 圆形颜色
    private int mCircleColor;
    // 圆环颜色
    private int mRingColor;
    // 圆环背景颜色
    private int mRingBgColor;
    // 半径
    private float mRadius;
    // 圆环半径
    private float mRingRadius;
    //进度圆环半径
    private float mProgressRadius;
    // 圆环宽度
    private float mBordWidth;
    //进度圆环宽度
    private float mProgressWidth;
    // 圆心x坐标
    private int mXCenter;
    // 圆心y坐标
    private int mYCenter;
    // 字的长度
    private float mTxtWidth;
    // 字的高度
    private float mTxtHeight;
    //文字颜色
    private int mTextColor;
    //文字大小
    private float mTextSize;
    // 总进度
    private long mTotalProgress = 100;
    // 当前进度
    private long mProgress = 100;

    public CountTimeView(Context context, AttributeSet attrs) {
        super(context, attrs);
        // 获取自定义的属性
        initAttrs(context, attrs);
        initVariable();
    }

    //属性
    private void initAttrs(Context context, AttributeSet attrs) {
        TypedArray typeArray = context.getTheme().obtainStyledAttributes(attrs,
                R.styleable.CountTimeView, 0, 0);
        mRadius = typeArray.getDimension(R.styleable.CountTimeView_radius, 80);
        mBordWidth = typeArray.getDimension(R.styleable.CountTimeView_bordWidth, 10);
        mProgressWidth = typeArray.getDimension(R.styleable.CountTimeView_progressWidth, 10);
        mCircleColor = typeArray.getColor(R.styleable.CountTimeView_circleColor, 0xFFFFFFFF);
        mRingColor = typeArray.getColor(R.styleable.CountTimeView_ringColor, 0xFFFFFFFF);
        mRingBgColor = typeArray.getColor(R.styleable.CountTimeView_ringBgColor, 0xFFFFFFFF);
        mTextColor = typeArray.getColor(R.styleable.CountTimeView_text_color, 0xFFFFFFFF);
        mTextSize = typeArray.getDimension(R.styleable.CountTimeView_text_size, 12);
        mTotalProgress = typeArray.getInteger(R.styleable.CountTimeView_total_progress, 10);
        mProgress = typeArray.getInteger(R.styleable.CountTimeView_progress, 10);

        mRingRadius = mRadius + mBordWidth / 2;
        mProgressRadius = mRadius + mProgressWidth / 2;
    }

    //初始化画笔
    private void initVariable() {
        //内圆
        mCirclePaint = new Paint();
        mCirclePaint.setAntiAlias(true);
        mCirclePaint.setColor(mCircleColor);
        mCirclePaint.setStyle(Paint.Style.FILL);

        //外圆弧背景
        mRingPaintBg = new Paint();
        mRingPaintBg.setAntiAlias(true);
        mRingPaintBg.setColor(mRingBgColor);
        mRingPaintBg.setStyle(Paint.Style.STROKE);
        mRingPaintBg.setStrokeWidth(mBordWidth);


        //外圆弧
        mRingPaint = new Paint();
        mRingPaint.setAntiAlias(true);
        mRingPaint.setColor(mRingColor);
        mRingPaint.setStyle(Paint.Style.STROKE);
        mRingPaint.setStrokeWidth(mProgressWidth);
        mRingPaint.setStrokeCap(Paint.Cap.SQUARE);//设置线冒样式，有圆 有方

        //中间字
        mTextPaint = new Paint();
        mTextPaint.setAntiAlias(true);
        mTextPaint.setStyle(Paint.Style.FILL);
        mTextPaint.setColor(mTextColor);
        mTextPaint.setTextSize(mTextSize);

        Paint.FontMetrics fm = mTextPaint.getFontMetrics();
        mTxtHeight = (int) Math.ceil(fm.descent - fm.ascent);
    }

    //画图
    @Override
    protected void onDraw(Canvas canvas) {
        mXCenter = getWidth() / 2;
        mYCenter = getHeight() / 2;

        //内圆
        canvas.drawCircle(mXCenter, mYCenter, mRadius, mCirclePaint);

        //外圆弧背景
        RectF oval1 = new RectF();
        oval1.left = (mXCenter - mRingRadius);
        oval1.top = (mYCenter - mRingRadius);
        oval1.right = mRingRadius * 2 + (mXCenter - mRingRadius);
        oval1.bottom = mRingRadius * 2 + (mYCenter - mRingRadius);
        canvas.drawArc(oval1, 0, 360, false, mRingPaintBg); //圆弧所在的椭圆对象、圆弧的起始角度、圆弧的角度、是否显示半径连线

        //外圆弧
        if (mProgress >= 0) {
            RectF oval = new RectF();
            oval.left = (mXCenter - mProgressRadius - (mBordWidth - mProgressWidth) / 2);
            oval.top = (mYCenter - mProgressRadius - (mBordWidth - mProgressWidth) / 2);
            oval.right = mProgressRadius * 2 + (mXCenter - mProgressRadius) + (mBordWidth - mProgressWidth) / 2;
            oval.bottom = mProgressRadius * 2 + (mYCenter - mProgressRadius) + (mBordWidth - mProgressWidth) / 2;
            canvas.drawArc(oval, -90, ((float) (mTotalProgress - mProgress) / mTotalProgress) * 360, false, mRingPaint); //

            //字体
            long count = mProgress;
            String txt = String.valueOf(count);
            mTxtWidth = mTextPaint.measureText(txt, 0, txt.length());
            canvas.drawText(txt, mXCenter - mTxtWidth / 2, mYCenter + mTxtHeight / 4, mTextPaint);
        }
    }

    /**
     * 设置进度
     *
     * @param progress
     */
    public void setProgress(long totalProgress, long progress) {
        mTotalProgress = totalProgress;
        mProgress = progress;
        postInvalidate();//重绘
    }
}

自定义属性如下：

<resources>
    <declare-styleable name="CountTimeView">
        <attr name="radius" format="dimension"/>
        <attr name="bordWidth" format="dimension"/>
        <attr name="progressWidth" format="dimension"/>
        <attr name="circleColor" format="color"/>
        <attr name="ringColor" format="color"/>
        <attr name="ringBgColor" format="color"/>
        <attr name="text_color" format="color"/>
        <attr name="text_size" format="dimension"/>
        <attr name="progress" format="integer"/>
        <attr name="total_progress" format="integer"/>
    declare-styleable>
resources>

声音播放控制

package com.spring.countdowndemo;

import android.content.Context;
import android.media.MediaPlayer;

/**
 * Created by Administrator on 2018/7/9.
 * 声音播放
 */

public class VolumeUtil {


    private MediaPlayer mediaPlayer;

    public void playMusic(Context context,int music) {
        if (mediaPlayer != null) {
            mediaPlayer.reset();
        }
        mediaPlayer = MediaPlayer.create(context, music);
        mediaPlayer.start();
        mediaPlayer.setVolume(1f, 1f);
    }

    public void releaseMusic() {
        if (mediaPlayer != null) {
            mediaPlayer.stop();
            mediaPlayer.release();
            mediaPlayer = null;
        }
    }
}

Activity中使用

package com.spring.countdowndemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity implements CountDownUtil.CountDownListener {

    private static final long DURATION = 10000;
    private static final long INTERVAL = 1000;

    private CountTimeView viewCount;
    private CountDownDialog countDownDialog;
    private CountDownUtil countDownUtil;
    private VolumeUtil volumeUtil;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        viewCount = findViewById(R.id.view_count);
        countDownUtil = new CountDownUtil(DURATION, INTERVAL, this);
        volumeUtil = new VolumeUtil();
    }

    public void startCountDown(View view) {
        countDownUtil.start();
    }

    public void startDialogCountDown(View view) {
        countDownDialog = new CountDownDialog(this);
        countDownDialog.show();
    }

    @Override
    public void onTick(long millisUntilFinished) {
        viewCount.setProgress(DURATION / INTERVAL, (long) (((double) millisUntilFinished / DURATION) * (DURATION / INTERVAL)));
        volumeUtil.playMusic(this, R.raw.audio1);
    }

    @Override
    public void onFinish() {
        viewCount.setProgress(DURATION / INTERVAL, 0);
        volumeUtil.playMusic(this, R.raw.audio2);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        volumeUtil.releaseMusic();
    }
}

项目源码地址https://github.com/qidingquan/CountDownDemo.git